Our coral studies with Montipora verrucosa will focus on several major questions: (1) histopathology allograft rejection with attention to identification of immunocytes involved, (2) characteristics of alloimmune memory, and (3) extent and characteristics of allogeneic polymorphism among separate populations. Continuing sea star (Dermasterias) work will emphasize (1) identification of immunocytes and their tissue sources and (2) specificity and duration of alloimmune memory toward integumentary transplants. Projects with genetically-defined mice will focus on immunogenetic characteristics of immune responses to the TNP and PC haptens conjugated to autogenous mouse serum albumin. This will include (1) fine mapping of the H-2I region genes involved, (2) levels of Ir gene action as shown by lymphocyte proliferation assays and antibody idiotype heterogeneity in high vs. low responders, and (3) hierarchy of dominant-recessive interactions among different H-2 haplotype combinations.